The present invention relates to a method and a device for automated assembling of cone half-bits of a valve of an internal combustion engine.
According to the conventional art, a valve of an internal combustion engine comprises a mushroom-shaped body including a stem on whose free end a cup element is secured having a conical inner surface tapering towards the mushroom shaped head of the valve, and an outer annular flange for abutment of one or more return helical springs for the valve, said cup element being secured on said end of the valve stem with the interposition of an annular body having an outer conical surface, also tapering towards the mushroom-shaped head of the valve, which is defined by two cone half-bits which are freely in contact with each other at a plane containing the axis of said annular body, said cone half-bits defining one or more inner circumferential ribs in their assembled condition which engage corresponding circumferential grooves provided on said end of the valve stem.
In his previous European patent application EP-A-0 708 228, the same Applicant has proposed a method for automated assembling of the cone half-bits on the valve stem, wherein the above mentioned two cone half-bits are mounted by causing them to slide on the valve stem while keeping them temporarily in a diverging condition, with their ends of lower diameter spaced apart from each other. In this previous patent application, the applicant has also proposed a device for carrying out the above mentioned method, comprising means for mounting said cone half-bits by causing them to slide on the valve stem while holding them in a diverging condition, with their ends of lower diameter spaced apart from each other, wherein said means included a tubular body adapted to be moved along an axis coincident with the axis of the valve stem and adapted to engage the annular flange of the cup element, said tubular body being further provided with a plurality of jaws which are elastically deflectable outwardly in a radial direction and having inner inclined surfaces, diverging from each other towards the mushroom-shaped head of the valve and adapted to engage the end surfaces of greater diameter of the two cone half-bits, said inserting device further including a pushing rod, slidably mounted within the tubular body and ending with a tip which is to be introduced between the two cone half-bits and for cooperation with the above mentioned jaws for holding the two cone half-bits in the said diverging position until they reach their assembling position on the stem.
The device which has been previously proposed by the Applicant is used in an automated assembling line for assembling an internal combustion engine. In order to check the proper mounting of the cone half-bits on the valve stem, it would be generally necessary to provide a further station for checking the quality of assembling in said line, downstream of the station for automated assembling of the cone half-bits.